package juc;

import java.util.Random;
import java.util.concurrent.Semaphore;
import java.util.concurrent.TimeUnit;

public class SemaphoreDemo {
    public static void main(String[] args) {
        Semaphore semaphore=new Semaphore(3);
        for (int i=1;i<6;i++){
            new Thread(new Runnable() {
                @Override
                public void run() {
                    try {
                        semaphore.acquire();
                        System.out.println(Thread.currentThread().getName()+"抢占车位");
                        TimeUnit.SECONDS.sleep(new Random().nextInt(5));
                        System.out.println(Thread.currentThread().getName()+"-----离开车位");
                    } catch (InterruptedException e) {
                        throw new RuntimeException(e);
                    }finally {
                        semaphore.release();
                    }

                }
            },i+"").start();
        }

    }
}
